I posted a while ago about some narly water spots on my windscreen which I couldn't shift. I tried everything from vinegar to toilet cleaner, bathroom cleaner etc etc and no joy. My boat mechanic gave me this stuff and I can't believe how easy it got them off. I followed up with rainex to help keep them away. Kinda embarrassed I let them get so bad....

Darren, the rain-x is really nice stuff when you don't have wipers. I've used it for years on rally cars. You do have to reapply it occasionally. It leaves the windscreen easier to get dirty though so I'm not sure it will fix your problem completely. I used to use it on my street cars but quit because of the haze.